Scale-up of Bioprocesses
Acetolactate —» CO
Acetoin + NADH + H+
At pH-values higher than 6.5 also acetate is formed.
b) Compare the residence time in the tube to the characteristic times for oxygen consumption and
substrate consumption. Assume that the dissolved oxygen concentration in the reactor is 10% of DOT,
and that the system is to be operated as a chemostat with a glucose concentration of 10 mg L"1
biomass concentration of 4 g L'1.
What are your conclusions?
c) The experiments by Amanullah et al, were in fact made as batch cultivations, with oxygen limited
conditions also in the stirred tank reactor. A control experiment, in which base addition was made in the
reactor instead of the loop was also made. The following yields were found
Residence time in loop
Yield of acetic acid
Sum of yields of acetoin
Biomass yield (g
pH control made in the stirred tank reactor instead of in the loop.
Discuss the results.
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